This invention relates to multilamp photoflash units and, in particular, to a more compact, cost-efficient array of photoflash lamps having a labeled housing construction.
Heretofore, multilamp photoflash units, of either the cube or array configurations, have comprised housing sections joined together by means of heat or sonic sealing techniques. For example, in the case of the flashcube, such as described in U.S. Pat. No. 3,327,105, the magicube, such as described in U.S. Pat. No. 3,730,669, and the flash bar, such as described in U.S. Pat. No. 3,857,667, a plurality of lamps and associated reflectors are mounted on a relatively horizontal base member and enclosed in a cubical or rectangular parallelopided-shaped transparent cover section which is joined to the periphery of the base section. The labeling for these units has comprised an indicia sheet insert located within the transparent cover above the lamps. In addition to serving as identification means, the labels were also adapted to function as flash indicators by including heat-shrinkable thermoplastic or foil over openings in alignment with respective lamps. For example, see German Auslegeschrift No. 1942465, published Oct. 2, 1977. Upon flashing of a lamp, the heat radiated therefrom causes the colored, (e.g., blue) plastic film to shrink away and disappear from the respective indicia sheet aperture to leave a void or dark spot identifying the lamp as having been flashed. Application of this approach to an indicia sheet located inside the transparent back of a planar array of lamps that is commercially available and referred to as a flipflash is described in U.S. Pat. No. 3,894,226. The overall construction of the flipflash unit comprises front and back plastic housing members with interlocking means for providing a unitary structure. The front housing member is a rectangular concavity, and the back housing is substantially flat. Sandwiched between the front and back housing members in the order named are a plurality of flashlamps, a multi-cavity reflector member, an insulating sheet, a printed circuit board having conductive patterns on one side to which the lamps are connected, and the indicia sheet. A similar planar array in which additional lamps are packaged in the same volume is described in U.S. Pat. No. 4,164,007.
In a unidirectional linear photoflash array described in U.S. Pat. No. 3,473,880 of Wick, the lamps are connected to a printed circuit board which comprises the rear housing of the unit and includes reflector cavities. A separate transparent sheet is then secured, such as by glue, to the front of the unit to enclose the lamps. Circuit patterns and terminals are disposed on both sides of the rear housing member. The patent does not appear to disclose any labeling with respect to the flash unit itself. U.S. Pat. No. 3,430,545 of Wick appears to illustrate a somewhat similar type of photoflash unit housing structure.
In a copending application Ser. No. 181,936, filed concurrently herewith and assigned to the same assignee, a compact, cost-efficient photoflash unit is described in which a horizontal linear array of flashlamps is enclosed within a one-piece housing member having a light-transmitting front portion folded over a back portion containing a plurality of lamp-receiving cavities in which the respective lamps are disposed. The housing is a formed sheet of plastic film having a linear fold disposed horizontally along the top of the array of cavities, which are selectively aluminized to provide a reflective coating on the cavity surfaces. A pair of lead-in wires for each of the lamps are connected to conductive circuit patterns on one side of a printed circuit board sandwiched between a set of tabs which run along the bottom of the front and back portions of the housing and are secured together. The sides of the housing are also secured so that the lamps, lead-in wires and connections are disposed within a secured enclosure, with a plurality of conductive connector terminals being disposed on a tab which projects from the printed circuit board and extends exteriorly of the secured enclosure. In this very compact enclosure configuration, the front portion of the housing includes a transparent window area that lies within a plane offset from the front housing tab and joined thereto by a transparent web. A means for securing the bottom portion of the housing is described in copending application Ser. No. 181,938, filed concurrently herewith and assigned to the same assignee, wherein one or more staples are disposed along the housing tabs. The staples extend through both tabs and the printed circuit board and are clinched onto the exterior surface of one of the tabs.
It is a purpose of the present invention to provide means for both labeling a photoflash unit and providing selective shielding of light radiated from flashing lamps through the transparent front portion of the unit housing. Such shielding may be desired in certain applications so as not to interfer with camera photocell operation; e.g., camera apparatus with exposure control systems including a photocell are described in U.S. Pat. Nos. 4,017,873 and 4,023,187. In the case of the aforementioned unit employing staple closure of the housing, a further purpose of the invention is to provide means for isolating the clinched ends of the staples to prevent contact with the hand of a person holding the array. Yet a further purpose of the invention is to enhance the usable light available from a compact photoflash unit.